Solve for $z$ : $z + 8 = 10$
Solution: Subtract $8$ from both sides: $ \begin{eqnarray} \\ z + 8 &=& 10 \\ \\ {-8} && {-8} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{8 + z} &\hphantom{=}& \hphantom{10} \\ z &=& 10 {- 8} \\ \end{eqnarray} $ Simplify. $ z = 2$